Help jointing a 5/4 twisted board

[Ray Scheller]

I'm experiencing a brain clamp when it comes to jointing a 5/4 piece of curley maple. The board measures 5/4 x 9" x 38" with a slight twist. I have plenty of board to remove the twist (I'm reducing it to 7/8" so I have ~ 5/16" to get rid of the twist) My question is how best to run it through the jointer to remove the twist. More importantly where do I put pressure on the board when I run it through the jointer. My brain tells me i should put pressure two opposite corners as the board runs through the cutters but like I said I'm not sure this is right. Can someone set me straight? Thanks.

[dan grant]

how big of a jointer do you have? i would try and flaten it as much as i could with a hand plane and then run it through

[Ray Scheller]

10" jointer.

[Peter Quinn]

I'd set your jointer for light passes and put a push block with a gripping bottom right in the middle of the boards length. Keep your weight there but don't push down more than necessary to keep the stock moving forward. 3-4 such passes should establish a flat reference over enough of the boards width to finish jointing using the outfeed table as your pressure point.

Don't know if that makes sense but it definitely works for badly twisted stock.

[Paul Simmel]

I'd set your jointer for light passes and put a push block with a gripping bottom right in the middle of the boards length. Keep your weight there but don't push down more than necessary to keep the stock moving forward. 3-4 such passes should establish a flat reference over enough of the boards width to finish jointing using the outfeed table as your pressure point.

Don't know if that makes sense but it definitely works for badly twisted stock.

This is exactly correct. Remember, outfeed as pressure point once enough flat has been established.

[J. Z. Guest]

I've had better luck putting the downward pressure at one of the corners of the board. If I put pressure in the middle, it wants to rock on the twist. I made no progress like this.

When I put the pressure on one of the corners, so that it wasn't trying to rock all the time, it worked much better. The flat reference surface was achieved in the same manner.

[David DeCristoforo]

I kinda do the same thing that Jeremy is describing but I hold down both "high" corners so that the wind is taken out more evenly. I realize that this means holding down the infeed side a bit which is usually a "no no". But I try and apply more pressure on the outfeed side. What I try to do is to knock down most of the high spots evenly and (grain allowing) I reverse the board for each pass. This way, I can keep the maximum board thickness. With a badly twisted board it's a bit of a "balancing act" until a few passes have been made.

[Rob Will]

When face jointing heavy twisted slabs I insert a shim under a low corner letting it protrude out the back end just a bit. The shim "splits the difference" between the low corners - usually 1/2 of the total twist.

Just before the shim gets to the cutter head I either let it slip out or let the cutterhead get it. You only need that particular shim one time becuase the next pass will require a thinner shim - again, 1/2 of the total twist.

Obviously this requires caution and I would make the shim out of something really soft. A section of a paint paddle works pretty well.

Before everybody jumps on me for creating a ballistic missle, here's what usually happens: Since the small shim is trapped under the main slab, when the cutterhead touches it, the shim either becomes saw dust or it kicks out just enough to be clear of the cutterhead.

If you leave the shim protruding you can put a finger on it to make it slide out before it gets to the cutterhead.

Using a shim allows you to apply pressure to the infeed side of the board with a push block. If I am doing something big, I usually get a helper to apply gentle pressure to the outfeed side and support the slab when it comes off.

Rob

[Nigel Tracy]

There is a free video treating this question at www.thewoodwhisperer.com (http://www.thewoodwhisperer.com) under DVD previews: Jointer and Planer Secrets.

His technique for jointing a twisted board is the first thing he talks about--check it out :)

[Terry Beadle]

If the board has a lot of twist, I would use a jack plane or scrub plane to remove most of the warp before hitting the jointer. You'll probably end up with a thicker result. The plane can get just a localized lift area so that when you go to the jointer, it will have a thicker plank to start with.

Again, this is for boards with a localized area that's causing most of the lift of the twist.

[Wayne Cannon]

His "Jointer and Planer Secrets DVD" video here has an excellent description of how to support the board on its two high corners so you preserve thickness by removing wood equally towards the low corners. I use a shaving as a wedge under one corner to get a stable "tripod", but I'll have to try his "small pile of wood chips".

One thing he doesn't mention is that you only want to do this until you get a small flat on the leading high corner of the board sufficient to keep the board from rocking (one pass, hopefully). Use pressure on that small flat corner to keep the same side-to-side "balance" and light pressure on the diagonally opposite trailing high corner until you have planed a small flat strip diagonally between those high corners. Use pressure against the planer's outfeed table along that flat diagonal strip from then on. Scribbling all over the surface of the board helps to monitor progress.

[Richard Niemiec]

Dan and Terry have the right idea, take some hand planes to it and get it most of the way, then take it to the power tools. Less chance of making a large mistake that way.

[Mike Henderson]

Dan and Terry have the right idea, take some hand planes to it and get it most of the way, then take it to the power tools. Less chance of making a large mistake that way.
I agree. When I have a board with a bad twist, I use a plane (often a scrub plane) to take off the high points. Makes it much easier to do the final flattening on the jointer. And it's actually pretty quick. You don't have to get the board perfect with the hand plane - just take out the worse parts.

Mike

[David DeCristoforo]

"... I insert a shim under a low corner letting it protrude out the back end just a bit. The shim "splits the difference"..."

That's what I'm talkin' about.... "splitting the difference". I just don't use the shim. As others have suggested, knocking the high spots off with a hand plane will work too but it seems like a pretty "fussy", time consuming way to go. "Balancing" the board on the high spots and knocking them down on the jointer is going to be a lot quicker. But then again, maybe some folks are not in such a hurry....

[Ray Scheller]

I used the technique of shimming both low corners and then running iit through the jointer. Since there wasn't a large amount of twist it took it out with one pass set at just a 1/16" depth. The shims didn't pose a ballistic threat because the helical cutters turned them to chips and not bullets. Man I love that cutter head. Twist is gone a the boards have been planed and glued up. I appreciate all the fine advice I got from you which is always right on the mark.

[Chris Friesen]

As others have suggested, knocking the high spots off with a hand plane will work too but it seems like a pretty "fussy", time consuming way to go.

Depends. If you've got a planing stop on your workbench, then it's just a matter of slapping the board down, grabbing a scrub or jack plane, and taking a few swipes at the high spots. With a sharp blade it's pretty straightforward to take off 1/16" at a time.

[Wilbur Pan]

Just to add to Chris' comment, it usually takes me less than five minutes to take care of the high corners of a twisted board with a hand plane.

You'll have to decide if that is too time consuming for you. ;)

[Lee Schierer]

This answer is sort of outside the box, but what I would do is to place the board on a known flat surface like another board and place a couple of shims under it to get rid of the rocking. Use double sided tape or hot melt glue to to hold the shims and twisted board in place on the sled board. Then run the entire sandwich through the planer to get one face flat or nearly so. Then run that face across the jointer to get truly flat before returning the piece to the planer for flattening the other side.